Signalr not sending data on Azure host

I am developing a web app where I use two hubs on a specific page to push notifications from server to clients and handle messages between clients. However I've come across a scenario oon my Azure production app service where the notifications hub won't transmit data back to the client even though the query is bringing the correct data.

Client code:

// Declare a proxy to reference the hub.
var notifHub = $.connection.NotificationHub;
var chat = $.connection.ChatHub;
var maxTabs = 10, index = 1;

// Start the connection.
$.connection.hub.start().done(function () {
    notifHub.server.getNotifications();

    /* Some more code irrelevant to this question */
});

notifHub.client.getNotifications = function (notification) {
    // Html encode display name and message.
    const notifications = JSON.parse(notification);
    // Add the message to the page.

    $("#Notifications").empty();

    notifications.forEach(function (notification) {

        const notificationDate = new Date(notification.CreationDate);
        let alertColor = "";

        if (((new Date) - notificationDate) < oneMinute)
            alertColor = "alert-success";
        else if (((new Date) - notificationDate) > oneMinute &&
            ((new Date) - notificationDate) < fiveMinutes)
            alertColor = "alert-warning";
        else if (((new Date) - notificationDate) > fiveMinutes)
            alertColor = "alert-danger";

        //language=html
        var notificationTemplate = "<div class ='alert " + alertColor + "' role='alert' data-request-id='{{RequestId}}' data-connection-id='{{ConnectionId}}' data-requester='{{RequesterName}}' data-group-name='{{RequesterGroup}}' data-request-date-time='{{CreationDate}}'><strong>Usuario</strong>: {{RequesterName}}<br /><strong>Fecha</strong>: {{CreationDate | datetime}}</div>";

        $("#Notifications").append(Mustache.render(notificationTemplate, notification));
    });
};

Hub code

public void GetNotifications()
{
    var db = new Entities();

    db.Database.Log = s => Debug.WriteLine(s);

    var companyId = Context.User.Identity.GetCompanyId();

    var notifications = (from notification in db.AgentRequestNotification
                             where notification.AttendedByAgent == false && notification.CompanyId == companyId
                             orderby notification.CreationDate 
                             select notification).ToList();

        Clients.All.getNotifications(JsonConvert.SerializeObject(notifications));
}

Code works perfectly on my local environment as seen on the following screenshot

But not on production environment

On my Azure App settings I've enabled Websockets and disabled ARR Affinity. I've debugged remotely with VS and this is the output I get, not sure what's causing about that WebSocketException shown after EF query log

      Opened connection at 1/15/2018 9:03:46 PM +00:00

SELECT 
    [Project1].[RequestId] AS [RequestId], 
    [Project1].[ConnectionId] AS [ConnectionId], 
    [Project1].[RequesterName] AS [RequesterName], 
    [Project1].[RequesterGroup] AS [RequesterGroup], 
    [Project1].[AttendedByAgent] AS [AttendedByAgent], 
    [Project1].[CreationDate] AS [CreationDate], 
    [Project1].[CompanyId] AS [CompanyId], 
    [Project1].[AttendedByAgentDate] AS [AttendedByAgentDate]
    FROM ( SELECT 
        [Extent1].[RequestId] AS [RequestId], 
        [Extent1].[ConnectionId] AS [ConnectionId], 
        [Extent1].[RequesterName] AS [RequesterName], 
        [Extent1].[RequesterGroup] AS [RequesterGroup], 
        [Extent1].[AttendedByAgent] AS [AttendedByAgent], 
        [Extent1].[CreationDate] AS [CreationDate], 
        [Extent1].[CompanyId] AS [CompanyId], 
        [Extent1].[AttendedByAgentDate] AS [AttendedByAgentDate]
        FROM [dbo].[AgentRequestNotification] AS [Extent1]
        WHERE (0 = [Extent1].[AttendedByAgent]) AND ([Extent1].[CompanyId] = @p__linq__0)
    )  AS [Project1]
    ORDER BY [Project1].[CreationDate] ASC


-- p__linq__0: '1' (Type = Int32, IsNullable = false)

-- Executing at 1/15/2018 9:03:49 PM +00:00

-- Completed in 25 ms with result: SqlDataReader



Closed connection at 1/15/2018 9:03:49 PM +00:00

The thread 0x1520 has exited with code 0 (0x0).
The thread 0x2904 has exited with code 0 (0x0).
Exception thrown: 'System.Data.SqlClient.SqlException' in System.Data.dll
Exception thrown: 'System.Net.WebSockets.WebSocketException' in System.Web.dll
Exception thrown: 'System.Net.WebSockets.WebSocketException' in mscorlib.dll
Exception thrown: 'System.Data.SqlClient.SqlException' in System.Data.dll
Exception thrown: 'System.Net.WebSockets.WebSocketException' in mscorlib.dll
Exception thrown: 'System.Data.SqlClient.SqlException' in System.Data.dll
Exception thrown: 'System.Net.WebSockets.WebSocketException' in System.Web.dll
Exception thrown: 'System.Data.SqlClient.SqlException' in mscorlib.dll
Exception thrown: 'System.Net.WebSockets.WebSocketException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in EntityFramework.dll
Exception thrown: 'System.Net.WebSockets.WebSocketException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in EntityFramework.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
w3wp.exe Error: 0 : Error while closing the websocket: System.Net.WebSockets.WebSocketException (0x800704CD): An operation was attempted on a nonexistent network connection
   at System.Web.WebSockets.WebSocketPipe.<>c__DisplayClass8_0.<WriteCloseFragmentAsync>b__0(Int32 hrError, Int32 cbIO, Boolean fUtf8Encoded, Boolean fFinalFragment, Boolean fClose)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.WebSockets.AspNetWebSocket.<>c__DisplayClass46_0.<<DoWork>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.WebSockets.AspNetWebSocket.<DoWork>d__45`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.WebSockets.AspNetWebSocket.<>c__DisplayClass32_0.<<CloseOutputAsyncImpl>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNet.SignalR.WebSockets.WebSocketHandler.<>c.<<CloseAsync>b__13_0>d.MoveNext()
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in EntityFramework.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in EntityFramework.SqlServer.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in Microsoft.Owin.Security.Cookies.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in mscorlib.dll
Exception thrown: 'System.Data.Entity.Core.EntityCommandExecutionException' in Microsoft.Owin.Host.SystemWeb.dll
The thread 0x219c has exited with code 0 (0x0).

Here's the SignalR client log

[17:56:53 GMT-0500 (Eastern Standard Time)] SignalR: No hubs have been     subscribed to.  The client will not receive data from hubs.  To fix, declare at     least one client side function prior to connection start for each hub you wish     to subscribe to.
[17:56:53 GMT-0500 (Eastern Standard Time)]     ignalR: Negotiating with '/signalr/negotiate?    clientProtocol=1.5&connectionData=%5B%5D'.
[17:56:53 GMT-0500 (Eastern Standard Time)]     SignalR: webSockets transport starting.
[17:56:53 GMT-0500 (Eastern Standard Time)]     SignalR: Connecting to websocket endpoint     'ws://samiweb.azurewebsites.net/signalr/connect?    transport=webSockets&clientProtocol=1.5&connectionToken=yKn2ns1bOenZLiUtCiOSSfQg    YCl%2FyVAvxKejSZx2x0svkyzIJJ85qjNMk7IBjy8Nes0Lg9W%2BUTAPW21z6rVHTwXbb4wxaZhVwn1J    vzrNra0WhYCuXMiu6kLYs0FWuRUy&connectionData=%5B%5D&tid=1'.
[17:56:54 GMT-0500 (Eastern Standard Time)]     SignalR: Websocket opened.
[17:56:54 GMT-0500 (Eastern Standard Time)]     SignalR: webSockets transport connected. Initiating start request.
[17:56:54 GMT-0500 (Eastern Standard Time)]     SignalR: The start request succeeded. Transitioning to the connected state.
[17:56:54 GMT-0500 (Eastern Standard Time)]     SignalR: Now monitoring keep alive with a warning timeout of 13333.333333333332,     keep alive timeout of 20000 and disconnecting timeout of 30000
[17:56:54 GMT-0500 (Eastern Standard Time)]     SignalR: Invoking saminotificationhub.GetNotifications
[17:56:54 GMT-0500 (Eastern Standard Time)]     SignalR: Invoked saminotificationhub.GetNotifications

Any help will be appreciated!

From your SignalR client log:

No hubs have been subscribed to. The client will not receive data from hubs. To fix, declare at least one client side function prior to connection start for each hub you wish to subscribe to.

AFAIK, the normal client log would look like: Client subscribed to hub 'notificationhub'. You could try to declare your client side methods prior to $.connection.hub.start().